With the development of semiconductor technology, computers have become able to operate with increasing lower power consumption. Under such circumstances, in the field of sensor networks, a small computer (a computer node, hereinafter referred to as a “node”) that operates making use of natural energy is known (see Japanese Unexamined Patent Application Publication No. 2011-103726 which is hereinafter referred to as Patent Document 1).
Meanwhile, in the field of distributed information processing, realizing the operation of each node making use of natural energy only is beneficial, since it can lead to a reduction in environmental load. Here, communication between nodes is a bottleneck in distributed information processing and it is desirable that a communication rate (communication bandwidth) between nodes is as large as possible. Thus, a technique for setting a suitable communication rate based on the remaining amount of power (the remaining amount of battery power) is known (see Japanese Unexamined Patent Application Publication No. 2010-263349 which is hereinafter referred to as Patent Document 2).